Damper assembly



Aug. 7, 1962 E. KAHN ET AL DAMPER ASSEMBLY 2 Sheets-Sheet 1 Filed Sept. 16, 1960 FIG.8

FIG.1

INVENTORS Elllo'r Kahn Alex Bobrowlch ATTORNEY E. KAHN ET AL DAMPER ASSEMBLY Aug. 7, 1962 2 Sheets-Sheet 2 Filed Sept. 16. 1960 FIG. 4

VII

FIG.7

h .m mm W m K .M M w 0 .l T NH lam/m 3,047,914 DAMPER ASSEMBLY Elliot Kahn, New Rochelle, and Alex Bobrowieh, Bronx, N.Y., assignors to Arrow Louver and Damper Corp, Brooklyn, NY, a corporation of New York Filed Sept. 16, 1960, Ser. No. 56,470 8 Claims. (Cl. 20-62) This invention relates to air or gas flow controlling means such as adjustable dampers and, more particularly, to a novel air foil section louver blade readily adjustable as to length and width and to a novel mounting frame for one or more of such blades.

With the wide variety of dimensions of louver or damper openings in modern building construction, it has been considered necessary to maintain a large variety of sizes of louver blades. While adjustment of the length of a usually contoured louver blade can be effected fairly easily to accommodate difierent widths of louver frames or openings, adjustments with respect to height variations are diflicult and expensive to make. In addition, in making adjustments as to height, it is diflicult to adjust the blades for proper overlapping and proper centering.

A further problem is the weight of the blade, particularly in wide openings requiring relatively long blades. The blades are usually an integral contoured extrusion, in the case of blades of non-ferrous metal such as aluminum, and to obtain the stiffness required for proper operation and freedom from warping, it has been necessary to use cross-sections increasing in weight in at least a direct proportion to the increase in blade length. Operation of the heavier section blades requires increased power consumption and heavier control linkage. All of this increases the installation and operating expense of the larger louvers.

' In accordance with the present invention, a novel louver assembly is provided including louver blades readily and inexpensively adjustable to nearly any length and to any Width within a wide range. In addition, the cross section of the blade, or its weight per unit length, remains at a constant low value over a wide range of lengths while the blade retains its stiffness even in the greatest I lengths.

More particularly, the louver blade of the present invention comprises five simply and easily assembled components, including two pairs of mating components. The first pair of components is a pair of hollow edge members of air foil cross section having bevelled free longitudinal edges, there being an integral outwardly opening angle extending along each inner surface of the member parallel toand uniformly spaced from the adjacent free edge. Near the bight of each member, a dove-tail slot is formed in one outer surface parallel to the apex of the air foil member.

The other pair of identical components are essentially flat and rectangular in plan forming center members I having, on either side of the center line of their inner radial slots having a depth equal to the height of the converging ribs. These slots are equal in number to the number of ribs on two center sections and are equally angularly spaced from each other. Preferably there are four slots at 90 to each other.

The angles on the inner surfaces of the edge members 3,047,914 Patented Aug 7, 1962 form pockets in which the edges of the center section have a tight frictional fit. First, all members except the shaft are cut to the desired louver blade length, the shaft being sufiiciently longer for bearing engagement in the louver frame. Then the center sections are cut to the width such that, when they are assembled with a pair of air foil edge sections, the blade will have the desired width.

The edge sections are assembled to a pair of oppositely facing center sections by forcing the out (if necessary) free edges of the latter into the pockets. The center sections are then assembled to the shaft by sliding their ribs longitudinally of the slot. The parts may be restrained against separation by the use of pop rivets uniting the center sections to the end sections. The finished blade has an air foil hollow cross-section, facilitating smooth flow of air. The bevelled edges of the edge section contribute to such smooth flow and reduce or substantially eliminate noise due to air flow. The dovetail slots in the edge sections receive conforming extrusions of flexible sealing material, these being on opposite sides of the assembled blade, to form air tight blade-toblade seals when the louver assembly is closed.

A further novel feature of the invention is the louver frame. For an installation wherein the-operating mechanism is attached directly to the blades between the side edges of the frame, top, bottom and both sides of the frame are formed from cut-to-length pieces of a channel preferably extruded of aluminum or aluminum alloy. The inner surface of the channel base is thickened in a zone centrally of the base and the outer surface of the base has a pair of dove-tail slots on either side of th center line.

Where the installation is to be operated by mechanism installed at one side of the frame and operating on a louver shaft, the operating side only of the frame is an angle, preferably of the same material as the channel, and having one leg identical with the channel base and thickened along its free edge. The other leg is somewhat longer than the channel flanges. The top, bottom, and other side are cut from the aforementioned channel section. I

The top, bottom and two sides of the frame are cut to size and brazed, welded, soldered, or otherwise united into a rectangular frame with the dove-tail slots aligned on its inner surface. The side members are suitably bored to receive nylon bushings for the blade shaft, and any side mounted blade driving mechanism is mounted inside the angle member. The dove-tail slots on the top and bottom members slidably receive conforming sealing strip extrusions, the particular slot selected depending on the direction in which the blades close. Sealing strips are also inserted in the slots of the side members of the frame. Conventional louver hardware may be used to interconnect adjacent blades, in which case the channel section will be used for all four sides of the frame.

It will be noted that only three different sections are required for the blade and only two different sections for the frame, a total of only five different sections thus being required to cover a wide range of lengths and widths of louver assemblies and a wide range of blade widths.

For an understanding of the invention principles, refer ence is made to the following description of a typical embodiment thereof as illustrated in the accompanying drawing.

FIG. 4 is an end elevation view of the blade center component;

FIG. 5 is a diametric section view of the rod or shaft;

FIGS. 6 and 8 are sectional views on the correspondingly numbered lines of FIG. 1;

FIG. 7 is a sectional view on the line 77 of FIG. 9; and

FIG. 9 is a view similar to FIG. 2 showing the angle.

Referring to FIGS. 1 and 2, a louver assembly or unit 10 is illustrated as including louver blades 20 mounted in a substantially rectangular frame including top member 11, side members 12 and 13, and bottom member 14. The blades 20 are oscillatable about the axes of blade shafts 35, described more fully hereinafter, which are rotatably supported in nylon bushings 15 set in uniformly spaced apertures in side frame members 12 and .13. One shaft 35 may have a link or crank 16 secured thereto for connection to manual or power operating means, and conventional louver linkage, generally indicated at 17, may be used to interconnect the blades 20 for unitary operation.

As stated, each blade 20 includes a pair of identical hollow air foil section edge members (FIG. 3), a pair of identical facing center members (FIG. 4), and a shaft (FIG. 5).

Referring to FIG. 3, edge members 25 are cut to length from an air foil section preferably extruded from aluminum, aluminum alloy, or other light-weight high strength material. Each member 25 has the shape of a relatively narrow V, with side walls 21 extending from a sharply curved bight 22. Walls 21. have a shallow outwardly convex curvature for a little over half the distance from apex on bight edge 22 to the free edges 23, and are substantially parallel over the remainder of their width. A short distance inwardly from free edges 23, which are bevelled inwardly, angle sections 24 project from the inner surfaces of walls 21 forming outwardly facing pockets 26 equidistant from bight 22. Near bight 22, one wall 21 is offset inwardly,

as at 27, and its outer surface has a dove-tail slot 28.

Each center member is also cut to length from a section illustrated in FIG. 4 and preferably extruded of the same material as the end members 25. Members 30 are rectangular in plan, and include a substantially flat wall or base 31 having a thickness substantially equal to the width of pockets 26 of members 25. Equidistant on either side of its center line, the inner surface of wall 31 has a pair of ribs 32 projecting therefrom and converging at a preset angle, preferably 90. The free edges of ribs or fingers 32 are preferably rounded as at 33. Between ribs 32, there is an arcuate fillet or bearing surface 34, formed with a radius centered at the intersection of the projected centerlines of ribs 32 and tangent with the inner surface of wall 31.

Referring to 'FIG. 5, shafts 35 are cut to length from a generally circular section preferably extruded from the same material as members 25 and 30. Shaft 35 has a radius just slightly less than that of surface 34, and is formed with plural radial slots 36 which are uniformly angularly spaced and equal in number to the ribs on a pair of members 30. For example, there are preferably four slots 36 at 90 spacings. The depth of slots 36 is substantially equal to the width of fingers or ribs 32. Slots 36 have rounded inner ends 37, and their outer edges are preferably rounded olf.

The members $11, 12 and 1-4 of the frame are all cut to length from the channel section 40 shown in FIG. 6, and which is preferably an extrusion of aluminum, aluminum alloy, or other light-weight, high strength metal. Channel 40 has a base 41 and flanges 42. Base 41 has a central enlargement 43 extending longitudinally of its inner surface, and its outer surface is formed with a pair of dove-tail slots 44 extending longitudinally thereof opposite enlargement 43 and equidistant on either side of the base centerline.

For the illustrated assembly having a side mounted operating mechanism, the side 13 of the frame is cut to length from the angle section 45 shown in FIG. 7 and formed of the same material and in the same manner as channel section 40. Angle 45 has a leg 46 whose section is identical to that of channel base 41 and mates therewith except for a short flange or rib 47. Leg 46 has an inner enlargement 43 and a pair of dove-tail slots 44. A second leg 48, is substantially wider than channel flanges 42, extends at right angles to leg 46.

The assembly of blade 20 will be described with reference to FIG. 8. First a pair of center sections 30 are arranged in opposed relation and their free edges are engaged with a frictional fit in the pockets 26 of a pair of edge sections 25. The latter are arranged with their dovetail slots 28 facing in opposite directions. The members are then secured against relative sliding movement by pop rivets, selftapping screws, or the like. Then a shaft 35 is slid into the assembly with its slots 36 receiving fingers 32 and its curved surfaces between slots 36 engaging fil-lets 34. The louver blade is now complete.

Blades of any desired length are formed by cutting sections 25, 30 and 35 to the pro-selected blade length. The blade width is adjustable over a wide range by cutting fiat walls 31 of members 30. In a typical practical example, one section 38 can be used for blade widths of 5" to 9". Such cutting is an easily performed field operation.

The sections 40 and 45 are cut to proper length and welded, brazed, or soldered together, with their dove-tail slots facing inwardly and aligned, to form the frame. Again, for a side mounted operating mechanism only one section 40 is used for three sides of the frame, with section 45 being used for the fourth side, or section 45 may be used for all four sides. Where a center mounted operating mechanism is used, the frame members may be any combination of the channel section or the angle section.

T shaped sealing strips 50, of suitable flexible material such as natural or synthetic rubber, or a suitable plastic, are provided with dove-tail heads fitting in slots 28. These strips 50 form an airtight seal between blades 20 when the assembly 10 is closed. Similar sealing strips 60 are slid into one slot 44 of each frame member 11 or 14 to engage the end blades when the assembly is closed, thus forming an airtight seal. Strips 60 may also be provided in the slots 44 or 44' of the side frame members between shafts 35.

It will be noted that the link 16 has one pair of axially aligned apertures configured to have a sliding non-rotatable fit over the louver blade shaft, and a second pair of axially aligned apertures arranged to receive a pivotal connection of the operating mechanism.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the invention principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

What is claimed is:

1. A louver or damper blade comprising, in combination, a pair of identical air foil shape edge members cut to length from a single air foil shape section having a relatively narrow V shape and including relatively deep side walls extending from a sharply curved bight; a pair of identical flat wall center members cut to length from a single flat wall section and substantially rectangular in plan, said center members being in facing opposed spaced relation; each edge of a center member being secured in merging relation to a wall of a different one of said edge sections; and a shaft cut to length from a single shaft section and extending longitudinally between and substantially centrally of said center sections; said shaft and the inner surfaces of said center sections having slidably interfitting rib and slot formations; said blade being adjustable as to width by trimming the edges of said center sections to conform to a preselected width; there being a pair of ribs on each center member converging at an angle of substantially 90; said shaft having four radial slots at 90 spacings.

2. A blade as claimed in claim 1 in which the side walls of each edge section have pockets adjacent their free edges receiving the longitudinal edges of said center sections.

3. A blade as claimed in claim 2 in which said side walls are substantially parallel adjacent their free edges, and said pockets are on the inner surfaces of the parallel portions of said side walls.

4. A blade as claimed in claim 3 in which the free edges of said side walls are bevelled inwardly.

5. A blade as claimed in claim 3 in which said pockets are formed by angle sections extending from the inner surface of said side walls.

6. A blade as claimed in claim 1 including an arcuate fillet between the ribs of each pair and circular about a center at the intersection of the projected ribs, the fillets engaging the arcuate portions of said shaft between each pair of slots.

7. A blade as claimed in claim 1 including a substantially rectangular frame rotatably mounting said shaft, and including at least one side cut to length from a channel References Cited in the file of this patent UNITED STATES PATENTS 450,316 Morstatt Apr. 14, 1891 2,026,311 Harris Dec. 31, 1935 2,230,707 Wallace Feb. 4, 1941 2,753,021 Westman July 3, 1956 2,759,574 Miller Aug. 21, 1956 2,822,587 Hallock Feb. 11, 1958 2,867,304 Greene Jan. 6, 1959 2,873,827 Adamson Feb. 17, 1959 OTHER REFERENCES Brown Sun Controls, page 11, Brown Mfg. Co., PO. Box 8777, Oklahoma City. 

